Even in a simulation, the world would be real

The Matrix as metaphysics (Chalmers); virtual is real; virtual realism

David Chalmers born 1966The 'hard problem': why is information processing accompanied by lived experience?

What it claims

The hypothesis that we are in a Matrix is not a sceptical hypothesis: it is a metaphysical hypothesis about what realises our world. Even simulated, we would have real hands, made of bits.

Why

What matters is what the simulation's computations do, not why they were built: tables and bodies exist there, made of bits.

The same idea through history

René Descartes1641Descartes imagines that a powerful being could deceive him about the sky, the earth and his body. For him this is a sceptical hypothesis: if it is true, his beliefs about the world are false. Chalmers argues the opposite for the Matrix.Hilary Putnam1981Putnam argues that if we were brains in vats always wired to a computer, our words might refer to the computer's processes, and our beliefs would be true. Chalmers says he reaches a similar conclusion by another route: not through the theory of reference but through the idea that the simulated world is a full reality.

David Chalmers2003The version presented here: the Matrix is a hypothesis about what the world is made of (bits, computations), not one that denies that it exists. He draws on the film The Matrix, but the argument applies to any simulation.

David Chalmers2022In the book Reality+, Chalmers extends the idea to all virtual worlds: digital objects are real objects, with real effects. This page relies mostly on the 2003 article, which can be read online.

In short

"Even in a simulation, the world would be real" is an argument by David Chalmers ("The Matrix as Metaphysics", 2003; Reality+, 2022, 2003) on the question "Is the world real?" (answer: virtual is real too). Its claim: The hypothesis that we are in a Matrix is not a sceptical hypothesis: it is a metaphysical hypothesis about what realises our world. Even simulated, we would have real hands, made of bits. According to AskPhilosophy's logic check (Z3 solver), the argument is valid only if one grants a premise the author leaves unstated (P4). AskPhilosophy presents 3 objections, 2 of them with a documented reply, and the original text behind each premise, checked word for word.

"The Matrix as Metaphysics", 2003; Reality+, 2022

Valid with an implicit premise

In the film The Matrix, humans live in a simulation and believe everything is real. People usually conclude: if we were in such a Matrix, our trees, tables and bodies would be mere illusions. David Chalmers says no. For him, the hypothesis "we are in a Matrix" does not say that the world does not exist: it says what it is made of. Just as physics tells us chairs are made of atoms, this hypothesis would tell us they are made of bits. Chairs would still exist. He calls this a metaphysical hypothesis (about what realises the world) and not a sceptical hypothesis (one that would take away our knowledge of the world). It is not a proof that we are not simulated: it is a thesis about what it would change.

click a premise to reject it

If you accept every premise, logic forces you to accept the conclusion. So the debate is about the premises.

Checked by a logic solver: the premises cannot all be true while the conclusion is false.
Without the implicit premise: Without P4, nothing rules out a world where chairs do exist (made of bits) but almost all our beliefs are still false, for example because the creators show us things unrelated to what we think we see. "Real" would not be enough to make doubt impossible.

P1: a Matrix would realise our physical processes through computations. P2: how these computations came about (as a simulation) is irrelevant. P3 draws from this that tables, chairs and bodies still exist. P4, hidden, says this is enough for the hypothesis not to be sceptical. So the Matrix does not destroy our knowledge of the world. What is debated: P2 (is a simulation really the thing itself?) and P4 (can a world created by others be called "real"?).

Analogy. An online game like Minecraft: the blocks and houses exist only in a computer, but they really exist, you can build them and they obey rules. Chalmers says that if our world were such a game, seen from inside, our houses would be as real as those blocks: they are real digital objects, not mirages.

Objections

Each objection is a conversation: click to see who replies and where the debate stands.

René Descartes 1641 · attacks the conclusion

Descartes judges that a powerful and cunning being who made me believe in a sky, an earth and a body could have deceived me about everything. In that case my beliefs about the world would be false: a hypothesis of this kind is sceptical, and one must look for a certainty that resists it.

Chalmers replies

see the argument

David Chalmers 2003

Summary: Chalmers compares the brain in a vat to a Cartesian mind, separate from the body. If my mind is in a dark room, that does not make my thought "I am in the sun" false: what matters are the processes the mind is connected to through its perceptions and actions. He concludes that the envatted being is no more deluded than a Cartesian mind.

Where the debate stands (our summary)Chalmers does not claim to refute the hypothesis: he writes that he cannot rule out being in a Matrix. The disagreement with Descartes is about its consequences: for Descartes it ruins knowledge of the world, for Chalmers it leaves it almost intact (he admits other hypotheses, like recent creation, that are partly sceptical). Disputed point, no consensus (our summary).

Robert Nozick 1974 · attacks the conclusion

Nozick proposes a machine that would give you, for life, every pleasant experience you want. Many refuse to enter: they want to do things and be someone, not just have the impression of it. For him, someone floating in a tank is "an indeterminate blob". One can draw an objection here: even if the simulated world is "real", what matters to us may be touching a reality that is not built by others.

no reply

see the argument

We have not yet found a direct reply by Chalmers in the texts.

The debate goes on (our summary) Nozick died in 2002 and speaks of the experience machine, not of the Matrix: the link is our comparison. In Reality+ (2022), Chalmers argues that life in a virtual world can have as much value as life outside a simulation (our summary of a reference we could not read; see the book's source). Whether "real" is enough to give value remains open.

Where the debate stands (our summary)The two positions do not quite contradict each other: Chalmers speaks of what exists, Nozick of what we value. The basic disagreement: can a life in a world created by others, but real, be as good as a life outside any simulation? Open point.

George Berkeley 1710 · attacks the conclusion

Berkeley argues that bodies and objects of the world exist only if perceived: their being is to be perceived or known. For him there is no hidden matter behind our ideas, and yet the world is not an illusion. If Berkeley is right, the question "what if there were a computer behind it?" does not even arise, and Chalmers's conclusion is reached by a shorter path.

Chalmers replies

see the argument

David Chalmers 2003

Summary: Chalmers notes the comparison with Berkeley (for whom appearance is reality) and admits reaching a similar conclusion. But he writes that he does not find it plausible that appearance is reality, and so does not endorse Berkeley's reasoning: he gets to his result by a different route.

Where the debate stands (our summary)Chalmers and Berkeley agree on the result: a perceived world is not an illusion. The basic disagreement: Berkeley denies there is any reality beyond what is perceived, whereas Chalmers keeps an external reality (the computations) that realises what we perceive. A disagreement Chalmers himself acknowledges (our summary).

What today's voices say

Defend it

David ChalmersDefends 'virtual realism' in Reality+: virtual objects are real objects.